In 2007, approximately three-quarters (76%) of all young people assessed their own mental health as excellent or very good. However, around one-quarter of all young people had a mental disorder* in the previous year (approximately 26% or 671,000 young people). The rate of mental disorders for people living in private dwellings gradually decreased from 26% in the 16-24 years age group to 22% in the 45-54 years age group, after which it declined more rapidly to 6% of those aged 75-85 years (as shown in Graph 1.1). Around one-quarter of people with a mental disorder in each age group had a severe level of impairment associated with their disorder, with the remainder having a mild or moderate level.

Graph 1.1 Prevalence of mental disorders(a)(b), Australia - 2007

(a) People aged 16-85 years who met criteria for diagnosis of a lifetime mental disorder and had symptoms in the 12 months prior to interview.(b) A person may have had more than one disorder.

The SMHWB focused on three main groups of disorders: Anxiety, Affective and Substance Use. The rates of each of these disorders differed with age. The rate of Anxiety disorders (15%) and Affective disorders (6%) for young people increased slightly to 18% and 8% respectively for those aged 35-44, after which rates declined in older age groups. The rate of Substance Use disorders, however, was highest in young people aged 16-24 years (13%) after which the rate dropped steadily to around 1% of people aged 65-85 years (as shown in Graph 1.2).

(a) People aged 16-85 years who met criteria for diagnosis of a lifetime mental disorder and had symptoms in the 12 months prior to interview.(b) A person may have had more than one mental disorder.

Young people were more likely to have Anxiety disorders (15%) and Substance Use disorders (13%) than Affective disorders (6%).

Young women were more likely than young men to have had any mental disorder in the year prior to the interview (374,800 or 30% compared with 296,300 or 23% respectively). Young women were also around twice as likely as young men to have an Affective disorder (8% compared with 4%) or an Anxiety disorder (22% compared with 9%). Substance Use disorders, involving Harmful Use of, or Dependency on, alcohol or other drugs, were more common in young men (16%) than in young women (10%) (as shown in Graph 1.3).

(a) People aged 16–24 years who met criteria for diagnosis of a lifetime mental^disorder and had symptoms in the 12 months prior to interview.(b) A person may have more than one mental disorder. The components when^added may therefore not add to the total shown.

The most common Anxiety disorder among young people was Post-Traumatic Stress Disorder (8%). This disorder arises as a delayed response to a distressing event that is outside the range of usual human experience (4), for example, combat experience, a life-threatening accident, or an unexpected death of someone very close.

Among young people, the most common Substance Use disorder was Harmful Use of Alcohol (9%). Harmful Use is a pattern of use that is responsible for (or substantially contributes to) physical or psychological harm, including impaired judgement or dysfunctional behaviour (4).

Bipolar Affective Disorder and Depression (both 3%) were the most commonly occurring Affective disorders among young people in the previous year. Bipolar Affective Disorder is characterised by repeated episodes in which an individual's mood and activity levels are significantly disturbed - on some occasions lowered (depression) and on some occasions elevated (mania or hypomania). Depression can occur in mild, moderate or severe episodes in which an individual experiences a state of gloom, despondency or sadness lasting at least two weeks. The person may experience a low mood, loss of interest and enjoyment, and reduced energy (4).

*This article focuses on young people who met criteria for a diagnosis of a lifetime mental disorder and who experienced symptoms in the 12 months prior to the survey.